What type of modification/conversion would it take to get these engines (in the United States) to burn biodiesel. I'm sure there are sensors that would be the first to go wacky at the first "wiff" of diesel.

Any recommended resources for futher/deeper understanding for how the Audi FSI engine is engineered?

Please don't totally flame me.
(1) - I almost purchased a diesel instead of my current 2.0T.
(2) - To me this engine kindof sounds like a diesel and I've read in at least one place, that the FSI is a diesel engine that is able to run on plain gasoline.

all the diesels ive seen have compression ratios of around 17:1 and if i recall correct the 2.0tfsi is 10.5:1. when the fuel is injected the way it is in this engine(fsi) it has a cooling effect to the air charge in the cylinder thus lowering pressure which will help prevent pinging so there would need to be a fuel heating element to to keep cylinder pressure high. there would also need to be beefing up of internal components and an aluminum head which the 2.0t has could be pron to warping. im sure there would be more but thats what i just thought of. although i havent investigated it much the HCCI gasoline engine technology may give you some more answers( an engine that under acceleration runs like a conventional gas engine but at crusing leans out the fuel ratio and cuts in more exhaust gas and the air fuel mixture ignites like a diesel would, with no spark, so the engine is more efficent) i will look for a link thou.

First, Thank you for the thoughtful response. It sounds like pressure is more of an issue than sensors.

I was chatting with a friend this day, It seems the engineering is kindof a trade secret.

I will post my progress for gathering more information.

Taking a very simple perspective - Listen. What is one hearing when the ear is near the 2.0t FSI. I hear a diesel...?

Thanks again.

diesels work on compression combustion. They do not have spark plugs. The compression at 17:1 or more genereates heat and spontaneous combustion.
The glow plug is used for starting the engine when cold.. to preheat the cylinder. Its not used like a spark plug.

In addition. today's modern diesels..especially
VW/Audi Diesels are running fuel pumps at over 29,000 psi. This would require a completely new fuel system, hose, lines, etc. Plus you have to scrap your exhaust as you will kill the Cat. and O2 sensors in seconds.